Telephone-exchange system.



F}. B..McB,ERTY. v TELEPHONE EXCHANGE SYSTEM. APPLICATION HLED JAN. 21,,19M.

1,156,416. I Patented Q0t.12,1915.

W/fnesss: t y Myer/foxy ,Mg. Frank/P. M- Be/fy- /M: my;

rnem

R. MO'BERTY, or An'rwnnr, BELGIUM, ASSIGNOB, T0 wnscrnmv ELECTRICCOMPANY, OF NEW YORK, N. Y., A CORPORATION OF ILLINOIS.

TELEIHONE-EXCHANGE SYSTEM.

Specification of Letters Patent. at t t 12, 5.

Application filed January-21; 1914. Serial No. 813,407

This invention relates to telephone eitchange systems and particularlyto systems wherein a desired connection isto be ex-. tended-or partiallyextended by means of' automatic switching apparatus at a central stationunder the control of manually operable apparatus at the substation ofthe subscriber desiring the connection.

, In BritishPatent specifications Noe 26,-

099 of 1910 and 21,259 of 1911 there are shown systems in which upon theinitiation of a call a calling line is automatically associated with aregistering and controlling mechanism. The designation of the callasdeterminedby the subscriberby the operation ofhis sending apparatusbeing received and stored, up in-such mechanism, which mechanism, 1nturn, controlsthe operation of the necessary automatic selector switchesto extend suchcalllng l ne as desired 1n ac-- cordance with suchdesignation.

As shown herein, this invention is applied tosystems of'the general typedisclosed in the British specifications referred to, but it will beunderstood by those skilled in the art that theinv ention is not limitedto such -by the setting of such systems but may. be applied 'to' systemswidely varying infcharacter, as, for example, to .systems in which theselector swltches themselves are directlycontrolled from the subscriberssl b-station.

. One of the, principal features of the invenan arrangement ofcirtionrelates to such cuits and ap'paratus that the controll ng c111-cuit between thesubsc'ribers sub-station and a straight metallic.circuit'withrequiring no ground connections whatever at thesub-station.-'

- Still another feature of the'1nvent1on,has

to do with a 'system in which the variably adjustable parts are "fpowerdriven that is,

rdrive'n-bypower mechanically supplied at suchparts and continuouslyavailable whereparts is accomplished orswitches' to be controlled is,

' cuit interruptions.

accurately and'positively although at a relatively high speed. I

More specifically theinvention also relates to a control system for suchvariably adj.ust able parts to be variably set'in consequence with asubscribers sub-station sender whereby such parts will be driven intothe proper set position under the control of two circuits, one under thecontrol of the subscriber and (the other locally controlled, suchcircuits operating alternately to set this part in mot on andsubsequently to bring it completely lnto a position corresponding to acomplete stage of operationof suchpart.

Acc'ording to another feature of the pres ent invention the. powerdriven selector switches are advanced in steps 'under the control ofcurrent variations produced ,in their clutch magnets by the sendingdevice, the extent of'mov'ement of the switches at each step being fixedindependently of the rate of operation of the sending device.

Other novel features of the invention will sufliciently appear in thedetailed description thereof hereinafter set-forth. The drawingsheretoattached,'forming' a part .of this specification, illustrates so much ofa telephone exchange system of the character described in the Britishspecifications 'above referred to as is necessary for a completeunderstanding of the invention. The subscribers sub-station is shown at10 and consists in part of the usual transmitter, re-

ceiver, induction coil, bell, condenser 'and hook .switch. I It alsoincludes the impulse sending device 11. This impulse sending device,which is diagrammatically shown, illustrates'a sub-stat on sender inwhich the operation consists of settingof a movable part thereof to a'.,point indicative. of the successive digits desired designating thedesired subscribers line. and in which after the [movable part has beenmoved to any given digit it'is released andrestored to normal, thecontrolling impulses being produced only in such restoring. movement andcorresponding in number to the digit to which such movable part hasbeen" set. In the sender shown such impulses are in the form of cir-More specifically in the sender shown, thehandle 12 will be moved in thedirection indicated by the arrow to a point from which in its restoringmovement the movable part will interrupt the contacts 1 3, 11 a numberof times corresponding to the digit to which such part has been set; Itwill be observed that these interruptions will be all shortinterruptions except the lastone before the movable part comes intonormal position. It might be noted that this last interruption is longonly in comparison to the other interruptions caused by the movable partand is, as a matter offact, relatively short. It will, furthermore,

be observed that in the form of sender shown the interruption of thecircuit during the forward movement of the movable part is theregistering and controlling mechanism,

such other apparatus not being shown, is a timing means such as forinstance suplence switch 21. This sequence switch is of the type shownin British specification No. 20810 of 1911, and therefore need not'b'e.described herein. This sequence switch 24 controls all of the sequenceswitch, contacts indicated below the dotted line of the drawings hereinand thereby determines at what time each of these registers should beenergized' Each of the registers is also struc turally precisely similarto the sequence switch shown in the British specification referred to,with the one exception,that the power magnet thereof, instead ofhavingblit .a single winding as in the sequence switch shown in theBritish specification, has two power windings differentially arranged,one adapted to be controlled by the external control circuit of suchsequence switch, and the other adapted to be controlled by the local orpositioning contact of the sequence switch itself. y magnet constitutesan electromagnetic clutch by means of which the power is applled to theregister switches by coupling thesw tch with a constantly rotating powershaft.

This difference is plainly illustrated in they drawings, and the utilitythereof will be hereinafter made clear Controlling the registers 21, 22and 23,

- and also controlling the sequence switch'24 through the intermediationof the slow op erating relay 25 is the rapid highly sensitlve line relay26. Also associated with there'ge i'stering controlling mechanism iswhat may be called a starting relay 27, the funct 1r of which will beherein described.

. Upon the initiation of a call the-calling This differentially woundpower,

McBert-yand 1,137,223 'of'April 27, 1915. When, therefore, thelinerelay26; was first energized by the establishment of circuit through thesubothersequence switch set in operation by the sequence switchassociated with the connect ing circuit but which, since it forms nopart of the invention herein is not shown, will then be set in operationto close the sequence switch contact 34.

To initiate a call the subscriber must remove his rbceiver from its hookswitch and the operations just described will take place inconsequencethereof. Immediately upon the closure of the sequence switchcontacts 31, 32 and 3st a circuit. will be established which may betraced from battery through the line relay 26, sequence switch contact35, sequence switch contact 34, sequence switch contact 31 bottom, outover the line, through contacts 13 and 14, the sub-stationtransmitter,the primary winding of the induction coil at thesub-sttdzion, back over the other side of the line and through sequenceswitch contact 32 top, to ground and back to battery. This will energizethe line relay 26. At" the sametime that this circuit is established acircuit is closed over sequence switch contact 33 andsequence switch'contact 36, to energize the starting relay 27. This latter relay uponits energization closes at its armature a circuit through sequenceswitch contact 37 bottom, driving such sequence switch out of its firstand, under the control of its localcontact 38, into its fourth position.During this movement of the sequence switch 24. no change takes place inthe circuit for line relay 26 hereinbefore described. v

In the registers of the type shown at .21,

22 'and23, and in. British specification No.

20,846 of 1911, a local spring controlled by the register, indicatedrespectively at 39,

-10 and 41, is opened only when its register is in its normal or someother proper stopping position-.' This spring 39, 4:0 or

41.1 is closed in all'other positions of its register. As the mechanicalconstruction and operation. of the registers form no part of thisinvention, their disclosure in the presnecessary. 1 The operation of'such registers andof theapparatus associated therewith is 'entspecification and drawings .does not seem fully described and showniii-patent to F. R.

Polinkowsky, No.

scribers sub-station, a circuit was closed for the register 21 frombattery overthe left hand'wmding of the power magnet thereof indicatedat42, sequence switchl'contact 43, r1ght hand armature and back contact ofthe slow operating relay and through the front contact and armature ofthe line relay 26; Immediately, therefo' the power magnet 42 of theregister 21 IS B II ergized and, power being thereupon applied. to themovablepart of such register, such closed. immediately that this contact39 is restoration.

closcda second circuit for the power-magnet -42 of such register iscompleted through the I, right hand winding thereof, wh ch winding isdifierentially arranged with respect to' th left hand winding thereof.Current is now passing through both of the windings of the power magnetand it will be dci-inergized and the movable part of the register 'will"come to a stop,.remaming' 11). such intermedlate positionhntil upon thedeen ergization of the line relay 26 the circuit through this left handwinding is opened, when, the cir cuit over the local contact being stillmaintained, the power magnet 42 is again energized and the movable partof the register will be brought into its first stopping position. Thereit will. come to a stop owing to the opening of the local contact 39,This deiinergization of the line ,relay 26 willin the normal operationof the system only occurwhen after the movable part of the sub-stationsender has been adjusted to the desired position, such part starts in,

its movement back to normal. Assuming that the subscriberhas moved themovable part of his sub-station sender to sucha position that fourimpulses, (three short and i one long breaks) will be produced in its IThe first break in the circuit will cause the denergization of the linerelay and the consequent movement of the registcr 21 into itsfirst'stopping position as just described. After this short'break, thecircuit will be again established to energize the line relay 26 which byattracting its ar mature will again start the movable part of theregister 21 infraction. This part will continue to move until it comesinto the second intermediate position when the local contact 39 is againclosed and the movable part will stop and await the subsequentdeenergization of the line relay 26 upon the second braking of thesubscribefis con trolling circuitf As we have assumed that thesubscriber has so set his sub-station sender that four impulses will beproduced it will be apparent that the register 21 Will upon the fourthbreaking of such circuit come into its fourth stopping position. 'At

switch contact 37 top to drive the sequence- ."switch 24 out of itsfourth and under the this time, however, owing to the longer c ientlylong to accomplish the! energization and the attraction of the armaturesof 7 the slow operating relay 25 over the back; 0

contact and armature of suchline relay. 26. The left hand armature ofthe relay 25 will thereupon close a circuit over sequence control of thecontactl38 into its sixth p'osition. This movement of the sequenceswitch- 24 opens the sequence switch spriilg 43 and closes the sequenceswitch contact 44 top thereby accomplishing what is known as the changeover 7. from dne register to an other andassociating the register-22with the line relay '26 in place of the register'21. The right handarmature of the slow acting relay 25 has meanwhile maintained thecircuitlfrom the relay to the register 21.npen.

'set position the longer impulse will betra-nsmitted over thecontrolling circuit and the slow operating relay 25 againenergized toaccomplish the change-over by driving the seq'uenceswitch 24 out of itssixth into its eighth position. In this position the .sequence switchcontact 44 bottom now being closedthe setting'of the register 23 will.take place under the control of the subscribers substation sender inprecisely anal- 1'10 ogous manner." 4

All three digits of the desired line now having been transmitted fromthe subscrib'ers substation sender and registered or stored up at there'gister 21;, 22, 23, such registers are in condition to controltheselec' tion of the desired line over the necessary automatioselectorswitches as will'be well understood by those familiar with the art.

As the sequence'switch 24 left its fourth 12o started in operation toextend the desired connection. Furthermore, when the sequence switch 24was driven out of its 8th po sition by the third 'energization oftheslow operating relay 25, it closed the sequence switch contacts 45bottom and 46. This latter contact completes a circuit to initiate theoperation of any other apparatus necessary 'or desirable to produce theproper operations to extend the desired connection. At this time thesequence switch contact 45 bottom is closed in order that after thesetting of the circuit extendingapparatus, not shown, the sequence 24and .all of the contacts controlled thereby maybe restored to normalcondition. -.It will be further observed that as the sequence switchmoved out of its first position the sequence switch contact .86 wasopened so that the starting relay 27'is no longer able to control thesequence switch 24 during the operation of the apparatus shown.

' line relay 26 will therefore into its ninth position, in whichposition it will rest until all of the other apparatus which may havebeen started in operation by the closure of the sequence switch contactin it's fifth position is restored to normal due to the prolongedbreaking of the circuit at the sub-station.. Then responsive to theclosure of a circuit including the sequence switch contact 46 thesequence switch 24 will be driven intoits normal position.

It will be observed that a the relative lengths of the interruptions toaccomplish the three difl'erent operations referred to are suchthat theshort interruptions will not be sufficiently long tocause theenergization of the relay 25. The longer interruption due to theoperation of the sub-station sender will be shorter than the time inwhich the sequence switch moves through one positi0n,.that is, forexample, fromposition 4 into position 6, or from position 6 intoposition 8. The restoring interruption due to the operation of thesubsc'rib'erls hook switch need only belong enough for "the sequenceswitch 24 to move to and out of its position 8. It may also be notedwith regard to the short interruptions-thatit is not necessary that thearmatures of the line relay 26 in responding to the short interruptionsdo any more than break the circuit at its first contact, it being whollyunnecessary for the proper operation of the system that any circuitbeestablished at the back contact there-- of except at the relativelylonger interruption pigthe circult by the sub-station sender orthe'interriq'ition of the circuit by the restoring of the receiver toits hook switch.

I claim': 1. The combination with a progressively operable switch,continuously operating power means and an electromagnet for associatingsaid power means with said switch, of means including a sending devicehaving a contact in circuit with a winding of said electromagnet adaptedby variable intermittent operation of said contact to variably adjustsaid switch, the extent of movement of said switch being independent ofthe rate of intermittent operation of said device.

'2'. The combination with a progressively operable switch continuouslyoperating power means and an electromagnet for associating saidpowermeans with said switch,

by intermittently varying the current .in' a winding of saidelectromagnet, and means for fixing the extent of movement of the switchat each step independently of the rate of intermittent current variationin said Winding. 1

3. In a telephone exchange system, an impulse. receiving'circuit, arelay in said circuit, a variably operable switch, a constantlyoperating power means, amagnet for-assoclating sald switch with saidpower means [upon the-closure of a single contact of said relay, 'meansfor opening-and closing said contact, and means, whereby after adefinite movement of said switch it will be stopped until said contactis'again closed.

7 .4. In a telephone exchange system, an impulse receiving circuit, arelay in said circuit, a .variablyoperable power-driven switch adaptedto be moved under the control of a single contact of said relay, and alocal circuit controlled by said switch itself adapted to stop saidswitch after it has of means for advancing said switch in steps moved adefinite distancein response to the closure of said contact anduntilsaid contact is again closed. f

5. In a telephone exchange system, a power-driven switch adapted to bemoved to any one of a plurality of positions, a differentially-woundelectromagnetic clutch forapplymg the power to said switch, an externalcontrol' circuit the closure of which will start saidswitch in motion,and a local circuit the closure ofwhich when such external controlcircuit is closed will bring such switch to a stop.

6. In a telephone exchange system, a power-driven switch adapted .to be;set to any one of a plurality of positions, a dif- I ferentially-woundelectromagnetic clutch to apply the power of said switch, an externalcontrol circuit including one of the windings of said clutch adapted toinitiatc'the movement of said switch from one position tothe next, alocal circuit closed by said switch between such positions andadaptedarsenic.

stop said switch intermediate of said positions-1f theexternal circuitis still closed Dand to cause the completion of the movejment of saidswitch to the next position ternal control circuit, a relay adaptedtofrom such setting impulses in duration but rali'ty ofautomatically-operating switches, an impulse producing-mechanism ata'diswhen such external control circuit isnzpen. 7. In a telephoneexchange system, a

. g power-driven switch-adapted to be moved to any one of a plurality ofpositions, an exclose suchcircuit to initiate the movement of saidswitch from one position to another,.

and means contained in such switch itself for stopping such switch whensaid relay is. maintained either energized or deenergized.

8. Ina telephone exchange system, a plu-.

of the same character.

9. In a telephone exchange system, a plu- I tant station adapted to setsaid switches. one

after another by impulses produced in the subscribers circuit by theoperation of said" mechanism andto cause the changeover from one of saidswitches to another by impulses differing from said setting impulses induration but of the same character, and a single relay included in thecircuit of said impulse transmitting mechanism controlling both thesetting of a switch, and the changeover from such switch to the nextswitch to be operated.

. 10. In a telephone exchange system, a plurality ofautomatically-operating switches, an im misc-transmitting mechanism, acir cuit .with which such switches are brought into association oneafter another, such switches being adapted to be set by means ofimpulses produced by said mechanism in such circuit, the changeover ofthe control from one of said switches to the next tobe associated withsaid circuit being caused by means of an impulse in said circuit simila: in character to the setting impulses but different in duration, anda single relay in said circuit directly controlling the changeover fromoneof said switches to the next'fand' the setting of each of suchswitches.

11. In a telephone exchange, system, a plu-' over, a relay in suchcircuit operated by short impulses therein to control the'settin of a.switch at that time'being controlle and timing means associated withsaid rerality ofjautomatically-operating switches, 'a control circuitwith which such switches are adapted to be associated one after anotherand -to beseverally controlled there-.'

lay and operated by a longer impulse in said a circuit to terminate thecontrol of one of saidrswitches and to place another of such switchesunder the control of said relay.

12. In a telephone exchange system, a plurality ofautomatically-operating switches adapted to be variably set one afteranother,

an external control circuit, a relay in said circuit operating inresponse to impulses v tlferein to control the setting of a switch atsaid relay and opera-tin .in response to the that time under the]control thereof, and a' sequence or steering switch associated with.

operation of such relay or, a longer impulse to transfer the control ofsaid relay from one of said switches'to another. 7

13.111 a telephone 'exchange system, the combination with aplurality ofmulti-posi-' tion automatic register switches, of an electromagnetic'clutchv for each switch haying two energizing windings, a controlcircuit including'a fast relay 'and an impulse wheel,

a circuit for energizing said clutch by one of its windings in anyposition of said 1 switch, said circuit leading through the frontcontact of said fast relay, a-local cir- .cuit including-theotherwinding dilferentially closed: by the switch itself in each intermediateposition, a slow relay, and a sejquence switch, said slow relayactuating said sequence switch after each series of impulses produced bysaid impulse wheel to successively transfer the front contact ,of saidfast relay to the succeeding registers.

In witness whereof, I hereunto subscribe my name this 30th day ofDecemben A. D. 1913.

I Witnesses:

L. F. WooDwAno,

FRANIK n. McBER'lY.

